1. Field of the Invention
The present invention relates to scanning probe microscopy, and more specifically, the present invention teaches a variety of carbon nanotube (CNT) devices and processes for fabricating CNT devices.
2. Description of Related Art
One prior art method for fabricating conventional scanning probe microscope (SPM) probes uses standard lithographic techniques and materials. The probes made by this method typically have a pyramidal tip shape and are fabricated from silicon. Some more specialized SPM probes include the etch sharpened conventional silicon probe, the adhesive or electrically fused attached carbon nanotube probes, directly grown nanotube probes and amorphous carbon spike probes.
The techniques and materials as defined by standard lithographic processes limit conventional probes. The materials typically used are silicon or silicon nitride. These materials are hard but brittle and can chip and wear relatively easily. The lithographic techniques as well as the materials limit the aspect ratio of these conventional probes. Lithographic techniques have a lower limit on feature size making high aspect ratio probes difficult to manufacture. More importantly, the brittle material found in etch sharpened conventional probes or focused ion beam milled conventional probes will break easily if the aspect ratio is too high.
The more specialized carbon nanotube (CNT) tips take advantage of some of the useful properties of the CNT, but prior art CNT attachment and/or growth techniques have little control over CNT length of CNT and optimizing imaging configuration. Amorphous carbon spike probes do not have the robust nature of and can break more easily then CNT tip probes.